Look closely at your hands — are they clean? It doesn’t matter how many times you wash them, your hands are still crawling with tiny organisms called microbes. (You may know microbes by their other names, such as “germs” or “bacteria.”) You can’t get away from them: Microbes are everywhere. But don’t worry — most microbes don’t harm you, and many actually help you stay alive.

Now, scientists say the microbes that live on our hands could be useful in a surprising way: fighting crime.